Automatic clutch mechanism



Aug. 17, 1937. w. E.` HAUPT 2,090,397

I AUTOMATIC CLUTCH MECHANISM Filed July4 25 1935 Patented ug. 17, 1937 uNmED STATESl PATENT OFFICE AU'liMVAZlIi',` CLUTCH MECHANISM Jersey Application July 25, 1933, Serial No. 682,127

11 Claims.

The present invention relates to automatic driveand clutch mechanisms, adapted to transmit power from a driving toa driven shaft, and although they possess operating characteristics and structural featuresthat particularly adapt them for motor vehicle and similar drives, they may be successfully employed in a wide variety of power transmitting drives. i f

More particularly, the present invention relates to automatic clutch mechanisms of the' type wherein a-driving member is mounted for axial movement of and is driven by a supporting member and is actuated by speed responsive mechanism to frictionally grip or clamp a driven member between it and the supporting member.

Automatic clutch mechanisms of this generalcharacter have been heretofore proposed, but they are so designed that the cost of producing them is excessive; they are so extremelyjbulky as to render them inapplicable to motor vehicle and like drives; they fail to transmit reasonableamounts of power in comparison with their size,

and their operating characteristics are such as tov render them wholly unsuitable for incorporation in motor vehicle or like drives. These major factors have so militated against these prior mechanisms that they have not been adopted in vpractice, and they accordingly have no successful commercial history.

A serious defect inherent in prior automatic clutch mechanisms of this general character repressurev builds up so rapidly between the engaging faces of the driving and driven members that a torque of rapidly increasing and widely fluctuating magnitude is accordingly transmitted to the driven member, and the latter and-the drive v mechanism and load to-which it is connected are accelerated in an uneven manner, lwith the result that shocks are transmitted to the drive mechanis'm and load, that are so severe in some in- J stances that parts thereof are actually distorted or broken under the stresses set up in them. The entire engaging operation. of these priorv mechanisms occurs over asmallrange of` speed of the driving member, and establishes a positive frictional coupling between the driving and driven members at a fairly low speed, with 'the result that if an internal combustion engine, a high speed electricjmotor, or a steam turbine is emplcyed as theprime mover,- the latter is accordingly compelled to accelerate the load when opery ating at a low torque delivery speed, and is often stalled by such engaging operation. 'Ihis type of operation moreover causes clutch engagement to occur with a harsh grabbing or chattering action, and this feature of itself renders such prior mechanisms wholly uni'lt for drives wherea smooth power transmission is desired.

Another highly objectionable feature attending y the operation of prior automatic clutch mechanisms of the character mentioned resides in the fact that the driving member is forced into engagement with the driven member in misalign- `ment, with the result that clutch engagement often occurs with a vchattering and grabbing action, the driven member is subjected to a twisting action with each revolution of the clutch mem bers and rapid Wear of 'the facing material is produced. This objectionable feature also often causes localizedareas of the engaging members to be heated to high temperatures with the result that the driving and driven members are warped or distorted and smooth clutch action is further yimpaired and the useful life oi' the mechanism altogether impossible to manually withdraw the driving member from'the driven member for declutching purposes. l Y

Prior automatic clutch mechanisms of this character that have been heretofore proposed possess a further lobjectionable operating feature that has militated against their adoption in many power drives. This feature resides in the fact that when the prime mover, or otherlmechanism that delivers power to the driving member, is 'operating at, or below, idling speed, it is impossible to establish a driving connection ,between 4the driving and driven shafts with such prior vclutch mechanisms. Itis clearly desirable that the mechanism be capable of effecting a driving connection 4between the driving and driven shafts regardless of whether the latterv are rotatingror stationary.v For instance, in motor vehicle'drives, it is frequently necessary to place the transmisy sion in gear'and tow or coast lthe'vehicle in order low or reverse gear when the engine is dead, and

propel the vehicle away from a dangerous location by means of the startingmotor..

It is a primary object of the present invention to devise novel automatic clutch mechanism that will automatically transmit torque of slowly increasing magnitude from a driving to a drivenY member, when one of the members is accelerated,

that are extremely ilexible and eicient in operation and adapt themselves to a wide variety of power transmitting drives, that are simple and rugged in design and stand up well in use, even under severe operating conditions; and yet that may be manufactured by low cost, quantity production methods.

A further object'of my invention is to devise l for use in clutch mechanisms of the type wherein a driving member is adapted to frictionally engage a driven member; a novel speed responsive mechanism for forcing the driving member into engagement' with the driven member in such manner that pressure is slowly built up'between the driving and driven members and a torque of slowly increasing magnitude is transmitted from the driving to the driven member when the driving member is accelerated.

It is a further object of my inventionI to provide automatic clutch. mechanisms of the type wherein a yielding connection is interposed between a speed responsive mechanism and a driving member; with` novel mechanism for equalizing the forces transmitted from the speed re- 40 Sponsive mechanism to the driving plate and for insuring the application of substantially uniformly distributed driving pressure to the latter.-

Another object of my invention is to devise for use in clutch mechanisms wherein a force applying mechanism is resiliently connected to a driving plate; a novel lspeed responsive mechanism for applying forces to the force applying mechanism.

It is a further object of the present invention to devise for use in clutch mechanisms of the type wherein frictional members or plates are adapted to be brought into engagement for transmitting power from a driving shaft to a driven shaft; a novel mechanism for forcing the plates into frictional engagement -when one* of' the shafts attains a predetermined speed, which is so designed that the parts thereof may be produced by other than precision methods without impairing their desired operating characteristics.

My invention further aims to provide clutch mechanisms o f the character whereinV frictional members or plates are adapted to be forced into engagement for establishing a driving connection between a driving and a driven shaft; with a novel, speed 'responsive mechanism for forcing the plates into engagement which has a substantially greatertravel or larger range of operative movement than. that of prior speed responsive mechanisms; and to design the clutch parts in such man-ner that the forces developed by speed,

responsive mechanism are transmitted smoothly to, and aredistrlbuted uniformly over Vthe plates,

even though the. clutch partsv are made by nonprecision, quantity production methods.

Another object is to provide automatic clutch mechanisms of the type wherein aspeed responsive mechanism is resiliently interconnected with, and is adapted to apply` forces to a driving plate; with mechanism for causing the forces applied to th'e driving plate by the speed vresponsive mechanism to build up in two or more stages.

My invention further aims to devise, for use in conjunction with automatic clutch mechanisms of the type havinga driving and driven member mounted for engagement and disengagement, and wherein .a speed responsive mechanism is resiliently interconnected with, and is adapted to apply driving forces to the driving member when the latter attains 'a predetermined speed, a novel mechanismior dlsengaging .the driving and driven members independently of the operation of the speed responsive mechanism when they are engaged under the inuence of the latter. f

Further objects of the present invention 'will become apparent as the specification proceeds in connection with the drawing, and from the appended claims.

In the drawing:

Figure 1 is a` longitudinal sectional view of a clutch mechanism forming part -of my invention.

Figure 2 is a view of the ring member-oi' the mechanism shown in Figure 1 as it appears when viewed from the left hand side of that ligure, with parts broken away and other parts in section to more clearly illustrate the structurev involved.

vFigure 3 is a fragmental sectional v iew of the; device disclosed in Figure 1, and -it illustrates oneof the Weight assemblies in its outermost or engaged position.

Figure 4 is a fragmental sectional view of a modied form of my invention.

Figure 5 is a fragments] sectional view of a further modication of my invention.

With continued reference to the drawing,

wherein like rference characters designate like parts throughout the several iigures, a bell housing "I encloses the clutch mechanism' and is adapted to be secured to a Aprime mover or supported in any suitable manner (not shown).

Rotational eiiorts are adapted to-be transmitted to the clutch mechanismthrough a drive shaft 2 whichin this instance comprises the driveshaft of an internal combustion engine, although other ysources of power may be employed. Drive shaft 2 is provided with an annular ilange 3, which is adapted to be secured to a y'wheel 4,or like rotatableA supporting member, by bolt assemblies I or other suitable securing means.

Shaft 2 is provided with an annular bore I which receives, a bearing assembly 'I for supporting the reduced end 8 of clutch shaft A9. 'nie other end of, the clutch shaft is supported in a suitable bearing I0 which is received in a recess III' in housing I. II of shaft 9 is a hub member I! having an annular ange I3. Flange Il is adapted tohave a driven disk I4 secured thereto. Disk lvl-is securedto ange I3 in any suita e manner, such as by rivets or the like.

Adjacent its outer edge, disk I i' carries faces AI5 and I6 which are made of a material having properties adapting it for the purposes and is described and claimed in Heinrich Patent 1,979,880, issuedNovember 6,

Mounted on a splined portion4 friction Facing I6 is adapted be frictionally engaged by a plate I'I which is mounted for synchronous rotation with the flywheel -in a manner to be hereinafter pointed out. Plate I'I preferably comprises a centrally disposed engaging portion I3 which is suitably machined for engagement with the facing I6. PlateI I'I is further provided with a threaded rim portion .I9. 'Ihreaded portion I9 is screw threadedly received in a rear- 10 wardlyextending flange 22, preferably integrally formed on flywheel 4. Plate I1 is also provided with a. central annular ange 23 which functions to strengthen the plate in' the area of the inner edge of frictional engaging face I6. Radial ribs l5 24- are also provided on plate I1 to further strengthen the latter andinsure that application of the driving pressure thereto will not tend to harmfully distort or warp it. j

The outer` rim of plate I1 is provided with apertures 25 which serve the dual purpose of providing means for locking the plate in adjusted angular position within flange 22, and for providing air passages to circulate air through the clutch to cool it and carry off vany particles of dust 25 which have been freed from the clutch faces incident to wear. 1

, Plate I'I is adapted to be locked in position by means of a bolt 26 which is threaded into ange 22 of the flywheel and is provided with a reduced 30 locking end 21 'which cooperates with one of the apertures 25. Irrespective of whether one or more locking-bolts 26 are provided, the parts are so designed that whenever a lock bolt is engaged with one of the recesses in plate I1, the remaining l apertures 28 of the ywheel align with apertures 25 formed in plate II`, and heated dust-laden air may be freely exhausted through the passages thuslformed. Adequate Ventilating orexhaust y parts are therefore insured regardless of which 4o aperture l25 happens to be cooperating with lock bolt 26.

The adjusting organization just described permits plate II to be adjusted toward and away from the ywheel and yet restrains the platev 45 against rotation when bolt 26 is locked in place.

Friction facing 151s adapted to be frictionaily y .29. Studs or driving lugs 32 are secured in apertures in flywheel 4 in any desired manner. 60 FromA the preceding description it will-be ap- .parent that plates I'I and 29 constitute the drivingf members of the clutch and are associated with `the dywheel in such a manner that they are caused to rotate .with it, and they cooperate with the 65 driven member to impart rotation to the clutch shaft 9 in a manner to be presently described.

' Positioned between the ywheel web and plate 4 29 isa disk-like ring member 35 which is mounted for synchronous rotation with plate 29 by means 7.0 of keys 436 secured in apertures in flange 3 of plate 2,9. Keys or lugs 36 cooperate with the walls of recessesv 31 formed-in ring 35. Recessesl are of sufllcient width to allow ring 35 to tilt or rock slightly angularly with respect to plate 29 75 for a purpose which will be hereinafter described.

Plate 29, on the face .opposite -to that adapted to engage friction face I5, is provided with circular bores 38 or the like which are adapted to'receive and center driving springs 39. The other ends of springs 39 are received in similar bores 40 formed in ring 35. The number of springs web. Positioned between `the heads of bolts 4I and the ywheel web areecompression springs The bolt and spring assemblies just de-: scribed-operate to urge the automatic plate to kthe left, and hold it 'out of contact with the driven member when the driving shaft is operating at or below idling speed. The hold-back assemblies accordingly cause springs 39 toV be lightly gripped between plates 29 and 35 when the clutch is disengaged and they accordingly maintain springs 39 in proper assembled relation under these conditions, and they will be hereinafter referred to as hold-back assemblies. The

-forces 'set up in springs 39 through the action of the hold-back assemblies causes ring 35 to be urged toward the iiywheel. l

Suitable speed responsive means are employed to cause the driving members to frictionally gripthe driven member-of the. clutch between them. Although anyl suitable speed responsive means is contemplated, lthe means preferably employed in the present embodiment of my invention comprise centrifugally operable means.' The particular centrifugally operable means employed comprises weight assembliesvwhich are suitably piv-` oted in a manner-that will allow them to operate in response to the speed of the flywheel'.

The preferred yform of speed responsive mechanism is associated with the automatic plate and comprises weights designated generally by the numeral 44. Weights 44 comprise lever portions 45 and head portions 46. Head portions 46 are normally clamped between the flywheel web and ringmember 35 when the clutch is stationary or running at idling .'speed; and under such conditions theparts appear as they are seen in FigureA 1, with the plates disengaged. Ring 35 is provided with upstanding chordally extending ribs v 4l which provide rectangular recesses 48 for the reception of heads 46 of weights 44. Heads v46 are provided with a fiat surface 49 which`cooperates with the'at bottom of recesses 48. Heads 46 are further provided with flat surfaces 5I which may behardened and polished, and Twhich are adaptd to cooperate with the fiat surface of' an annular recess 52 formed in the ywheel web.

Recess 52 is preferably machined in the flywheel web to provide surfaces against whichl heads 46 may react Vwhich is exactly normal to theiaxis ofV the mechanism and it is to be understood that it is unnecessary to provide such recess lwhere the flywheel web or other reaction member has a suiiiciently accurately formed surface. The outer sides of heads 46 are cut' at an angle or relieved in order Atoprovide a knife-like edge 53. Knife edges 53 Acooperate with the outer dihedral angles formed by the bottoms of recesses 48 and the -outer upstanding ribs/41. Knife edges 53 provide pivots or fulcrumsabout lwhich weights 44 swing in response tocentri'fugal force during operation 45 will now bey described.

clearance. This adjustment'is originally made f at the factory or at the point where the clutch is assembled. After the clutch has been in use and facings i5 and I6 become vthin as the result of wear, this adjustment may be eiected to compensate therefor and reestablish proper plate clearance. Adjustment may be conveniently made when housing I is provided with an inspection .opening 59 normally closed by a suitable cover 9| Secured to housing I I by cap screws 62 or the like. A wrench or other suitable tool may f be inserted throughl opening 59 and lock nut 26 may be removed and plate I1 yrotated in the proper direction ance. The adjustment just described shifts the whole plate assembly and therefore does not in'any wayto establish proper plate clear- I change the compression on the driving springs or the hold-back springs. 'I'his feature is highly desirable since it is essential for satisfactory operation that the springs exert at all times a predetermined force relative to each other in order that the clutch will notengage at too low or too high an engine speed. It is also necessary for satisfactory operation to 4keep the final engagement pressures of the clutch mechanism up to apredetermined minimum in order to .secure' 40 non-slipping drive.

It vwill be observed that the ,clutch disclosed i'n Figures 1 3 isa fully automatic ciutcn, there being n manual control means associated therewith. The operation of this clutch 'mechanism i Operation Rotation of shaft2, under the inuence of the prime mover causes flywheel 4 and the clutch driving members orplates I1 and 29 to rotate there--y with. When the flywheel reaches a predetermined speed of rotation weights 44 swing or rock outwardly about their knife edges 53. The speed at which this rocking action of weights 44 takes place is predetermined by the compression of holds back springs 4I', and the mass ofA weights 44.

. Springs 4i are adapted to exert the hold-back action'previously described and the magnitude of 'this action ,is determinedfby the strength of springs 4I. This action exerts a movementresisting iniluerice upon .plate 29, and it is apparent that by increasing or decreasing the tension'on the springs 4I' it will be apparent that the speed of engagement ofv the clutch may be C5 varied. v

As the weights pivot, or 'rock about their knife Aedges 59 in response td centrifugal force, reaction faces 5I of weight heads 49 fulcrum and undergo a slight sliding action on the faces of recesses-Ska and knife edges 59, due to their engagement and fulcruming action upon the flat surface of recesses 49, force ring away from ywheel 4. Actuation of the weightsinlthis manner through the medium o f springs 39; causes automatic plate -29 to also move away from the ilywheel against the action of projecting lever aoeaso? the hold-back springs 4I into its automatic engaged position in engagement with friction facing I5 of disk I4. Axial movement of plate 29 in this manner under the influence of weights 44 causes driven member I4 toundergo axial movement and to be frictionally clamped or gripped between drivi ing members I1 and 29'.

During the phase of-operation just described, plates 29 and 35 preferably undergo substantial unitary movement, and the pressure built up in springs 99 is relativelylow because of their relatively great strength or stiiness in comparison with that of hold-back spring 4I'.

After the driven member" is thus clamped or gripped between the automatic plate and plate I1, further 4movement of `plate"29 is arrested, and further rocking movement of weights 44 forces ring 35 further away from the ywheel against the action of springs 39 and builds up pressure in the latter. A corresponding pressure is built up between the plates and torque of comparatively slwly increasing magnitude is smoothly transmitted from shaft .2 to shaft 9, and the latter and the load coupled thereto are smoothly picked up by the prime mover. When weights 44 rock out.-

Wardly and build up pressure in springs 99, and

between the plates, should they rock unevenlyor to an unequal extent, plate may tilt and take a. slight angular position with .respect to plate 29 and thereby tend to compensate for such uneven action.v To this end, plate 95 is designed to float between pressure plate 29 'and ilywheel 4, i. e., plate 35 is not rigidly connected to any other of the clutchparts but is retained in place solely by springs 39 and the heads 46 of weights 44. Due to this novelconstruction plate 35 is capable of unimpeded free axial tilting which permits p1ate'35to distribute any localized application of force d ue to the unequal outward( -movement of one or more of the weights over a' large area of thev plate thereby compressing several of the springs 99 and applying a more equalized transmitting force to plate 29. If plate 35 were not allowed to tilt or rock in this man ner, and operate -to distribute the forces applied by weights 44, localized forces might be applied to plate 29 with. resultingpoo'r clutch operation.

As theprime mover accelerates and weights 44 swing outwardly and cause the driven member to be clamped between the automaticwplateand the positive plate, as previously described, movement of the automatic plate away from the ilywheel is resisted -by the hold-back springs 4I'l acting through the medium of the :driving springs and ring 95. 44 under control. Hold-back springs 4i' therefore, in addition-to predetermining the speed of the mechanism ai:l operation ls initiated, exert asteadying influence upon the clutch parts.

When the iiywheel attains a predetermined speed, weights 44 move into contact with the iiywheel rim, as seen in Figure 3, and the parts'are so designed that when this occurs the pressure between the plates is of such magnitude as to hold them in non-slipping engagement.

When it is desired to disengage the. clutch mechanism,` the prime mover is allowed to decelerate and consequently the flywheel deceleratestv When the predetermined idling speecl is reached, hold-back springs 4I' move weights 44 into their normalpositions and cause disengagement of .the clutch platea Although I have illustrated and prefer to employ thecen'trifugally operable mechanism dis- This restraining action holds weights which automatic engaging' l-the invention the driving springs 39 are replaced by a Vpair of springs 1I and 12. Springs 1I are gripped between plates 29 and 35 by the holdback assemblies in the manner previously described, while springs 12 are preferably, although l 15 not necessarily, loosely disposed with respect to their seats `in plates 29 and 35, when the prime mover is operating at or below idling speed.l

If desired, springs 4I' may be stiff enough to.

preload springs 1I and/or ,12, or springs --1I and/or 20 12 may be preloaded by any other suitable means without departing from the spirit of the present invention.- The operation of this device is as follows: Y

When weights 44 swing or rock outwardly 25 about their knife edges in response to centrifugal force, plate 29 is moved into engagement with facing I of the driven member I4 and grips the latter between plate 29 and plate l1 in the manner previously described. While this portion of 30 the operation is taking place, springs 1I are not compressedappreciably and therefore the clearance between the ends of springs 12 and plates l 28 and 35 is maintained. i Further rocking of weights 44 causes pressure to 35 be built up in springs 1I,. which causes an initial light and smooth engagement of the clutch plates, and a torque of comparatively low and slowly increasing magnitude is initially transmitted to shaft 9. As the springs 1I are further com- 40 pressed the magnitude of the'torque transmitted gradually increases, and shaft 9 is picked up evenly and without grabbing with a slipping drive. When ring 35 has been moved suiiciently to the right under the influence of weights 4 4 it grips 45 secondary springs 12, which are preferably stiier than springs 1I between it and plates 29, and at ,this time the first stage of clutch engagement operation maybe said to be at an end, and the second stage initiated.

50 Further movement ofplate 35, under influence 0f weights 44causes pressure to build up at a actual practice these stages may be designed to merge into each other so completely thatv the change from one to the other is imperceptible, 65 and a very smooth clutch engagement accordingly is obtained. When it is desired to disengage the clutch mechanism, the flywheel is decelerate'd, and when the' predetermined idling speed is reached hold-back springs 4I move weights 44 70 into their normal positions and cause disengagenient in the manner described in connection' with the mechanism illustrated in Figures 1, 2,v

and 3.

In` Figure 5 of the drawing, IhaveY illustrated '15 the mechanism shown in Figures 1, 2 and 3, as it appears when provided with a modified backing plate having declutching mechanism associated therewith. In this device rim 22 of the flywheel is adapted to s crew'threadedly engage an annular ring member 15. Ring member 15 is provided with apertures 25a that cooperate with locking screw 26, and apertures 28 provided in a flywheel rim in the manner described with reference to Figures 1-3. suitably secured to the ring 15 is a cover member 16. The securing means in this instance comprises cap screws 11, although any suitable securing means may be used.

A positive plate 18 is provided for engagement with face I6 of the driven member. Plate 18 is resiliently backed by relatively stiif spring assemblies 19 one end of which seats in recesses 8l l in the positive plate, and the other ends are received in similar recesses 82, in cover plate 16.

Plate 18 is mounted for synchronous rotation with the iiywheel by means of driving lugs 80 secured in recesses in vmember 15. Plate 18 is further provided with suitable stud members 83 which are located adjacent the periphery thereof.

. Studs 83 are adapted to be encircled by hardened washers 84 which cooperate with the curved ends 85 of the throwout levers 86. Washers 84 are adjustably held in place on' pins 83 by means of castle nuts 81. The inner ends'of levers 86 are provided with curved faces 88 which-are adapted to contact, with a hardened race member 89 of a throwout assembly designated generally at 9|;

and which may take any suitable form. Throwout assembly 9i is mounted for axial movement fon a stationary supporting sleeve 98 and adapted to be moved axially by means of the usual throwout fork and clutch pedal organization (not shown). Since throwout bearing 9| forms no part of the present invention a detailed description thereof will beV omitted.

Lever members 86 are rotatably mounted intermediate their ends onpins 92 which\are received in ears 93 of bracket members 84. Bracket members 94 are suitably secured to cover 16 in any suitable manner such as by means of rivets or the like. Cooperating with levers 86 are springs f 95 which insure contact of the levers with washers 844 during al1 phases of operation. One end of springs 95 are received on bosses' 96 provided on levers 86, and the other ends are received in recesses 91 in cover member- 16. Cover member 16 is further' provided with slots 98 to allow free and unobstructedoperation of the throwout levers. n l tures 99 in alignmentwith pins 83 which provide access to nuts 81 in order to adjust the throwout levers to take up for wear. In the present embodiment three throwout levers are provided. Levers 86 may be adjusted in this manner to establish proper angular relation of the plates with respect tothe mechanism, and they may also be adjusted in this manner to bring them intov proper angular-position after' facing wear compensating adjustments have been effected through. rotating member 15v within the flywheel.

The'clutch pedal (notshown) ispreferably provided wlth a. latch mechanism for holding the throwout assembly in its intermediate position shown in Figure 5 against the action of springs 39. With the parts held in this position, and with the flywheel operating at or below idling speed, the parts appear as they are seen in- Figure 5, with the clutch disengaged.

As the flywheel isaccelerated above idling speed, weights 44 rock outwardly in 'response to centrifugal force in the manner previously set The cover member is provided with aper- 1 forth and cause driven disk I6, to be frictionally gripped between plates 29 and '18. As the accelerating operation proceeds, torque of' increasing magnitude is transmitted to the driven shaft through the pressure built up in springs 39 and v19. Although springs 39 and 19 have been illustrated." as being of substantially equal size and strength, it is to be understood that they may be of different capacities vto provide any desired type 10 of clutch engagement, depending upon 'the requirementsiof the particular installation involved. Likewise, double spring units of the general type illustrated in Figure 4 may be substituted for springs 39 and/or 19 if desired without in any l5 way departing from the spirit of the present invention.

As the engaging operation just described is taking place, plate 18 is moved to the n'ght, which relieves levers 86 of the` pressure of springs 19,

20 and springs 95 move the inner ends of vlevers 86 to the left, out of contact with the throwout assembly thereby relieving the latter of pressure.

If for any reason it is desired to declutch the mechanism, the clutch pedal may be depressed so as to-move the throwout assembly to the left and thereby cause the inner ends of levers Y8&5 to fulcrum. about pins 92 and withdraw plate 'I8 from facing I6 against the action of springs 19. In order to prevent springs 39 from advancing plate 29 into engagement with facing |15 ywhen the declutching operation is taking place, I preferably provide a plurality of headed members IDI which extend through aligned apertures |03 and recesses |04 in the ywheel web and plate 35 respectively, and are threaded into plate 29. Members lillV are designed so that they do not interfere with movement'of plate 2 9 to the right 'during its automatic .engaging operation, but corne into play and stop against the flywheel and 40 arrest movement of plate 29 when the declutching operation is being effected. A f

f If it is desired to establish a driving connection between shafts 2 and 9 when the flywheel is operating at or below idling speed or is stationary, the clutch pedal latch may be actuated to allow it tobe retracted through the medium of springs 19 acting through levers 86, and the throwout assembly. 'I'his operation allows plate 'I8 to be vforced into engagement with facing I6 and thereby grips the driven member between it andA plate 29.

Although I prefer to use the type of speed responsive mechanism of the type illustrated, itis to be understood that if desired any other suitable type of speed responsive mechanism may be employed" to apply forces to the force transmitting member without departing from the spirit of thepresent invention. For instance pivoted ,weight members, supported on' the flywheel or other .reaction member and having portions extending through apertures therein and engaging plate 35 may be used if desired or springs `39 may be constructed so as to extend through the ywheel apertures and engage the pivoted weight members.

Although I have disclosed, and prefer` to employ clutch .mechanisms of the single plate" type; i. e. clutch mechanisms of the character."

,wherein a pair of driving plates or members cooperatewith a singledriven plate, it is to' be distinctly understood that -myinvention may be readily embodied in clutches of the well known multiple plate type, wherein three or more driving members or plates cooperate with two or more driven plates without departing from the spirit of the present invention or from the scope of the appended claims.

I The invention may be embodied in other specic forms without departing from the spirit or essential characteristics thereof. The present embodiments are therefore to be-considered in all respects asillustrative and not restrictive, the scope of the invention being indicated by the appended claims rather than by the foregoing description, and all changes which come within the rlneaning and range of equivalency of the claims are therefore intended to be'embra'ced therein.

What is claimed and desired to besecured by f United States Letters Patent is:-

1. In an automatic clutchl mechanism, in subcombination, adriving member, a force transmitting member and a reaction member mounted for synchronous rotation'and for'relative axial Y to force said members into frictional engagement when one of said members attains a predetermined speed comprising speed responsive mechanism operably associated with said members; and means for equalizing the magnitudes of the forces applied to said membersby said speed responsive mechanism and for establishing av yielding engagement pressure between said members when they are engaged under the inuence of said speed responsive mechanism, said last named means being disposed between said speed re'- sponsive mechanism and said Idriving member and comprising a member mounted for axial and slight tilting movementand which is adapted to have forcesapplied thereto by said .speed responsive mechanism. 3. In a device ofthe character described, driving and driven members mounted for engagement and disengagement; 'means adapted to force said membersv into engagement when one of .said members attains a predetermined speed:

comprising .a plurality of speed responsive elements; means mounting said elements for movement outwardly in response to centrifugal force substantially in' planes parallel to the axis of the mechanism; and means for yieldingly transmit'tingforces from said elements to said driv- Y ing member, said last named means comprising af force transmitting memberV against which said elements are adapted to act, said-force transmitting member being mounted for axial movement and also being capable of slight rocking movements in response to uneven application of forces thereto by said elements.

- 4. In an automatic clutch mechanism, a driving member; a'driven member; disposed between said driving member and a second driving member;

speed responsive means; resilient means for establishing a yielding connection between said speed responsive means andV said rst driving member; means tor resiliently urging' saidvsecond driving member toward said first named driving member for establishing a yielding engagement pressure between said members when they are engaged -ao ing member; a driven member; means adapted under the inuence of said speed responsive means; means for disengaging said members against the action of 'one of said resilientl means; and means for limitingv movement of one of said driving members toward the other said second driving member under the inuence of one .of said resilient means.

5. In an automatic clutch mechanism, in subsponsive mechanism having a plurality of ful-l cruming elements clamped between said driving member and said force distributing member and adapted to apply reactive forces against said driving member and active forces against said force distributing member at a distance from the vaxis of rotation substantially equal to the distance of saidresilient means from said axis. v

6. In an automatic clutch mechanism, a driving member; an automatic plate mountedvfor synchronous rotation with said driving member; a driven plate; a force distributing member; rcsilient means between said force distributing member and said automatic plate, speed responsive means for engaging said plates, comprising a pluralityof levers having fulcrum portions disposed between a`nd acting against said driving member and said force distributing member; said 40 levers extending through apertures in said driving member and having weights carried on the other end thereof; resilient means connected between said driving member and said automatic plate for resiliently opposing the force of said speed responsive means on said force distributing member. d

7. In an automatic clutch, a pair of axially spaced driving members having means securing them together for synchronous rotation; a driving plate and a force transmitting element disposed between said members and adapted to un, dergo axial movement with respect thereto; a driven plate disposed between and adapted to be frictionally gripped between one of said driving members and said driving plate; resilient means interposedlbetween' said force transmitting element and said driving plate; and speed responsive means, operable to apply active forces to said force transmitting element and reactive forces to .said other driving member, for exerting clutch engaging forces upon said driving -and driven plates through said resilient means, said securing means being operable to allow said driving members to be adjusted axially toward and away from each other, to thereby vary the pressure applied to said plates by said speed responsive means.

8. In an automatic clutch mechanism, a driving member; a driving plate; means for securing said driving plate to said driving member; a second driving plate mounted for synchronous rota- -tion with said driving member a driven plate;

force Adistributing means; resilient means disposed between said` force distributing means and said second driving plate; speed respnsivelmeans forengaging said driving and driven plates when said driving member is accelerated through a predeterminedspeed range; said means for securing said rst-named driving plate `to said driving memberbeing operable to adjust said first-named p driving plate axially with respect to said driving member to compensate for clutch wear.

9. .'Ihe combination as set forth in claim 8, wherein said first-named driving plate is screw threadedly engaged in said driving member.

10. In an automatic clutch mechanism, driving and driven members mounted for engagement and disengagement; an automatic driving plate; at least one speed responsive means adapted to .force said plate and said driven member into engagement when said driving member is accelerated through a predetermined speedrange;

means disposed between said plate and said one speed responsive means and reacting against said one speed responsive means for establishing a yielding force transmitting connectionA between said one speed responsive means and said driving member, said connection including at leastl two 'springs, one of which is not preloaded, whereby the forces exerted by said one speed responsive means are applied to said member in stages.

11. In an automatic clutch mechanism, driv- 'ing and driven members mounted for engagement and disengagement; an automatic driving plate; at least one speed responsive means adapted to force said members into engagement when said driving member is accelerated through a predetermined speed range; andl force transmitting means disposed between s aid plate and said one speed responsive means and reacting against said one speed responsive means for establishing a yielding force transmitting connection and operable to establish a two-stage yielding engagement pressure between said members when said driving member is accelerated through said speed range, said force transmittingwmeans also being operable to^ cause said engagement pressure to buildup at a greater rate in the second stage than in the first stage.

WILLIAM E. HAUPT. 

